Eye Examinations

The comprehensive eye examination at Barnard Levit Optometrists is designed to investigate thoroughly both the health of your eyes & visual system and the refractive status of your vision. Please explore this section of our website to find information more specific to your needs.

Your appointment will usually take forty five minutes to one hour. Please also allow more time than this for choosing spectacles.

Please also note that if you are a contact lens wearer, you will need to be allocated additional time to for this aspect of your eyecare. Please mention that if you are a contact lens wearer when you make your appointment.

History & Symptoms

invite you to describe any symptoms or visual difficulties you might be experiencing

ask about your general health and whether you are taking any medications. It is helpful if you bring with you a written list of medications as some medications can cause ocular side effects.

ask about your past eye health and optical correction history.

ask about family eye history, particularly with regard to macular degeneration, cataract and glaucoma

discuss with you your visual requirements and their optical implications. For example, your optometrist will be interested to know if you use a computer, drive, have specific hobbies or play sports. There are optical as well as eye safety issues associated with most visual activities, particularly some sports such as squash, tennis, golf, cycling and sailing.

The health of your eyes and visual system

A comprehensive series of examinations are carried out to investigate the health of the external and internal eye as well as your visual system as a whole.

Eye movements and eye muscle balance. These tests are fundamental to understanding how your two eyes work and move together.

Visual fields using either a screening strategy or a full threshold Humphrey SITA test the gold-standard test used to investigate the integrity of the visual pathway from the eye to the cortex at the back of the brain. This is a fundamental and routine test used to detect a wide range of eye and neurological disease.

Pupil reflexes. This is an important routine neurological test. We use the IRISS Medical Technologies Pupil Analyser to assess pupil sizes when necessary

Anterior chamber angles are screened to assess risk of a future acute glaucoma. If the angles appear narrow your optometrist will assess further using a gonioscope - a special contact lens with mirrors to view into the angle - or using the Zeiss HD-OCT anterior segment technology which gives a 2-D cross sectional scan of the angle

Viewing the anterior chambers by gonioscopy

Eye pressures.Intraocular pressures are measured using either the screening,“air-puff” tonometer, the Goldmann applanation tonometer or, if we need a more accurate measurement, the Pascal DCT tonometer, a precision instrument, from Switzerland which automatically compensates for the thickness of the cornea. It should be noted that although measuring the eye pressure is an important test it must not be considered a test for glaucoma because up to 50% of patients with glaucoma have “normal” eye pressures

Checking eye pressure with Goldmann applanation tonometry

Corneal thickness may be measured with the Zeiss Cirrus HD-OCT as an important part of glaucoma screening

Examination of the external eyes by biomicroscopy to examine the integrity of the eye lids, cornea and conjunctiva

Internal eye examination is carried out using binocular indirect slit lamp biomicroscopy to check the crystalline lens, the vitreous gel and retina. The practice has a Haag-Streit BQ-900 video microscope.This examination is designed to assess and diagnose conditions such as cataract, posterior vitreous detachment and a wide range of retinal or optic nerve conditions including primary open angle glaucoma (POAG), retinal tears/detachments, optic nerve anomalies and macular disease such as macular holes and degeneration. Sometimes we will need to dilate your pupils using an eye drop to obtain an improved view. For all of these last conditions, diagnosis is carried out with the support of the results of other tests including visual fields, eye pressures and optical coherence tomography (OCT).

Microscope view of the cornea and anterior chamber

The comprehensive eye examination includes a photograph of the retina and choroid (layer under the retina) of all patients using the latest technology Optos Daytona laser scanning camerawhich assesses up to 85% of the retina without the need to use eye drops.This is carried out routinely at each eye examination for documentation and monitoring purposes.This latest instrument enables early detection of some conditions due to its hyperfluorescence facility.

Daytona Optomap wide field retinal imaging

An additional, non-routine investigation which is sometimes advised is Optical Coherence Tomography (OCT) using the Zeiss Cirrus HD-OCT. Barnard Levit was the first optometry practice in Europe to use OCT technology which allows for a “non-invasive biopsy” of the macula, optic nerve or retinal nerve fibrelayer. With a resolution of just 5 microns this cross-sectional analysis through the retina, rather than just the view of the surface, gives a highly detailed analysis of retinal and optic nerve tissue aiding early diagnosis of macular degeneration and glaucoma as well as providing accurate monitoring of these and other related conditions.

Standard of Vision and Refraction

At Barnard Levit we not only perform a detailed and in-depth refraction which can include further analysis using the Zeiss PolaTest, but also our patients also have the benefit of the Zeiss i-Profiler Aberrometer and corneal topographer. This not only objectively measures your prescription for low order aberrations (short-sight; long-sight; astigmatism) but also measures high order (more complex) aberrations (trefoil; coma; secondary astigmatism; spherical aberration). Knowledge of all the aberrations of eye enables your optometrist to optimize your spectacle prescription to give enhanced vision using standard and advanced technology such as Zeiss i-Scription lenses. Patients' Vision (unaided) and Visual Acuity (corrected) is assessed using a range of tests including LogMar, contrast sensitivity and a range of paediatric (children's) tests.

Careful refraction for optimum Rx

Binocular vision

Your optometrist will assess your eye movements and binocular vision to ensure the two eyes are working together as well as possible. If there are any weaknesses or imbalance we can often treat them with eye orthoptics (evidence based eye exercises) and /or specific prescription glasses incorporating optical/prismatic elements to perfectly integrate binocular vision. See Orthoptics & Vision Therapy.

Review of the findings and advice

At the end of the examination, your optometrists will discuss the results with you, offer advice on optimizing your vision if required with spectacles or contact lenses, explain any relevant eye health matters and answer any questions you may have.

Discussing retinal findings with a patient

Spectacles

Once your optometrist has obtained a precise and balanced spectacle prescription, it is important that this is translated into spectacles that are precisely made and dispensed. For optimum vision, aberration free lenses such as Zeiss Individual™ are often advised in single vision or multifocal forms. Our Dispensing Opticians will measure the distance between your visual axes and eye position relative to the eyewear chosen,to the nearest 1/10thmm, using Zeiss RVT technology so that your spectacles can be made with the highest precision to ensure optimum visual comfort. Spectacle frames of all types and a range of qualities are available from economy styles to bespoke hand-made frames from materials ranging from high quality plastics and stainless steel to alpha titanium, gold, hardwoods or buffalo horn. See EyeWear Frames and Spectacle lenses